This invention relates to an apparatus and method for work hardening a thin steel endless belt which is used in a belt caster for casting molten metal into metal products.
Twin belt continuous casting machines include a tundish which receives molten metal from a furnace, the molten metal being subsequently fed from a nozzle into a casting zone. The casting zone includes a mold which is formed by a pair of opposed movable belts and a pair of opposed movable side dams. The back sides of the belt are cooled by a coolant (typically water) which facilitates removing heat from the solidifying molten metal. The molten metal solidifies in the casting zone and emerges as a metal product which is subsequently moved out of the casting zone at casting speed. One type of belt caster is an endless belt caster which is disclosed in several patents issued to the Hazlett Strip Casting Corporation such as U.S. Pat. No. 4,002,197 and others.
The belts used in these endless belt casters are typically made of steel and must, on the one hand, be thin enough to aid heat transfer from its casting side to its cooling side and, on the other hand, be strong enough to sustain the rigors of casting. In addition, it would be desirable to stretch the belt below elastic yield in order to prevent distortion during casting.
What is needed therefore is an apparatus and method for work hardening an endless belt for use in a twin belt caster that provides a strong, distortion free belt surface that will enhance the quality of the cast metal product while at the same time having a long useful life.